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view src/core/ngx_times.h @ 6080:4296627f385a stable-1.6

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Core: fixed a race resulting in extra sem_post()'s. The mtx->wait counter was not decremented if we were able to obtain the lock right after incrementing it. This resulted in unneeded sem_post() calls, eventually leading to EOVERFLOW errors being logged, "sem_post() failed while wake shmtx (75: Value too large for defined data type)". To close the race, mtx->wait is now decremented if we obtain the lock right after incrementing it in ngx_shmtx_lock(). The result can become -1 if a concurrent ngx_shmtx_unlock() decrements mtx->wait before the added code does. However, that only leads to one extra iteration in the next call of ngx_shmtx_lock().
author Roman Arutyunyan <arut@nginx.com>
date Wed, 04 Feb 2015 16:22:43 +0300
parents d620f497c50f
children 777202558122
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_TIMES_H_INCLUDED_
#define _NGX_TIMES_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


typedef struct {
    time_t      sec;
    ngx_uint_t  msec;
    ngx_int_t   gmtoff;
} ngx_time_t;


void ngx_time_init(void);
void ngx_time_update(void);
void ngx_time_sigsafe_update(void);
u_char *ngx_http_time(u_char *buf, time_t t);
u_char *ngx_http_cookie_time(u_char *buf, time_t t);
void ngx_gmtime(time_t t, ngx_tm_t *tp);

time_t ngx_next_time(time_t when);
#define ngx_next_time_n      "mktime()"


extern volatile ngx_time_t  *ngx_cached_time;

#define ngx_time()           ngx_cached_time->sec
#define ngx_timeofday()      (ngx_time_t *) ngx_cached_time

extern volatile ngx_str_t    ngx_cached_err_log_time;
extern volatile ngx_str_t    ngx_cached_http_time;
extern volatile ngx_str_t    ngx_cached_http_log_time;
extern volatile ngx_str_t    ngx_cached_http_log_iso8601;

/*
 * milliseconds elapsed since epoch and truncated to ngx_msec_t,
 * used in event timers
 */
extern volatile ngx_msec_t  ngx_current_msec;


#endif /* _NGX_TIMES_H_INCLUDED_ */